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A117980
Legendre-binomial transform of (-1)^n for p=3.
1
1, 0, 3, 0, 0, 0, 3, 0, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 9, 0, 0, 0, 9, 0, 27, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 9, 0, 0, 0, 9, 0, 27, 0, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 27, 0, 0, 0, 27, 0, 81, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
OFFSET
0,3
COMMENTS
a(n)=a(3n)=a(3n+2)/3; a(3n+2)=0.
LINKS
FORMULA
a(n)=sum{k=0..n, L(C(n,k)/3)*(-1)^k} where L(j/p) is the Legendre symbol of j and p.
PROG
(PARI) A117980(n) = sum(k=0, n, kronecker(binomial(n, k), 3)*((-1)^k)); \\ Antti Karttunen, Sep 20 2019
CROSSREFS
Sequence in context: A219551 A200221 A158678 * A065032 A007514 A336642
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Apr 06 2006
STATUS
approved